The invention relates to an apparatus for coupling an optical fiber to a laser light source. More particularly, this invention relates to a quick disconnect coupler which can mate optical fibers of varying size to a laser light source, the coupler of this invention being able to detect information concerning a characteristic such as size, of the optical fiber being mated to the laser light source.
In the field of medicine, it is desirable to insert optical fiber catheters into the human body to probe and inspect various portions of the body. One such technique is to surgically insert a catheter into a main blood vessel and pass the catheter to various organs, such as the heart, for inspection. A technique being used today is to insert an optical fiber catheter attached to a laser energy source into the body and then use laser pulses to destroy materials blocking blood vessels or remove any material towards which the optical fiber catheter directs the laser energy.
Obviously, each catheter can be employed with only one patient. Accordingly, the catheters are disposable. Since the size of the blood vessels in human bodies varies according to age and physical attributes, different size fiberoptic catheters are needed. Therefore, a quick connect/disconnect feature for attaching the fiberoptic catheter to a laser light source is needed.
The optical coupler for attaching an optical fiber catheter to a laser source must accurately align the optical fiber with the light source to permit near 100% coupling of the laser light into the optical fiber. This requires a particularly accurate coupler.
Various types of quick connect tubing couplers are known in the art. An example is U.S. Pat. No. 3,032,359 to Cator, May 1, 1962, which discloses a snap action coupler for tubing having a locking means to prevent leakage at the coupler. A more recent example is shown in U.S. Pat. No. 4,114,853 issued Sep. 19, 1978 to Medvick wherein a closely fitting male member provides a releasable coupling with a female member. The known tubing couplers are designed to provide a repeatable leak free seal between two tubes. No use with optical fibers is made or suggested.
Optical fiber couplers such as those disclosed in U.S. Pat. No. 4,435,036 to Sasakawa and U.S. Pat. No. 4,607,911 to Rhodes show the use of a two part connector, the two parts being coupled by threaded engagement. Neither coupler is of a quick disconnect design nor does the coupler provide any information about the optical fibers being coupled. Likewise, the directional coupler disclosed in U.S. Pat. No. 4,423,922 to Porter uses a threaded engagement of an optical fiber and does not provide any information about the fiber being coupled.
When employing fibers of varying size, it is important to know the size of the fiber being attached to the laser source. When employing lasers to vaporize or otherwise remove material, the energy density per laser beam pulse is critical. Too great an energy density may damage human tissue which was not to be removed or cause damage to the optical fiber. As the size of the fiber varies, the energy density per pulse will also vary. Therefore, in addition to accurately aligning and coupling an optical fiber catheter to a laser light source, the optical coupler should recognize the size of fiber catheter to which it is coupling so that the energy emitted by the laser can be controlled.